@article{CM_1977__35_1_39_0,
     author = {Abels, Herbert},
     title = {On a problem of {Freudenthal's}},
     journal = {Compositio Mathematica},
     pages = {39--47},
     publisher = {Noordhoff International Publishing},
     volume = {35},
     number = {1},
     year = {1977},
     mrnumber = {466399},
     zbl = {0352.22003},
     language = {en},
     url = {http://www.numdam.org/item/CM_1977__35_1_39_0/}
}